All you need to know about the weather in Brazil is right here. 

If you are planning to visit Brazil, keep in mind that the country lies in the tropics and has a warm climate all year long. This applies to all the regions, except some places in the south. From São Paulo up north you'll be able to go to the beach at anytime. Rio de Janeiro's ocean waters tend to be cooler than the Brazilian average, but in the northeast sea water is always warm.

Brazil has three main climate zones, each of them with its own rainy season. In Rio de Janeiro and the south of the country it rains more in summer, from October to May. Winters are dry and mild in Rio but it can get very chilly in the south. Temperatures are low in Santa Catarina and Rio Grande do Sul. In the northeast, on the other hand, it's hot all year long. The wet season goes from May to July but the rest of the year the sun shines most of the time. Finally, it can rain at any time in the Amazonas, as it lies on the Equator. However, the wet season officially goes from December to May.